This application relates generally to connectors and more particularly to a connector which mounts to the surface of a disc drive printed circuit board and which provides a solderless connection between the disc drive printed circuit board and a printed circuit board which is external to the disc drive.
In recent years mobile computing devices, particularly laptop computers and hand held computing devices, have become extremely popular for a wide variety of home, business and commercial uses. Such devices commonly include a main central processor unit along with additional support circuitry which are mounted on a printed circuit board, commonly called a motherboard. Additionally, these devices typically contain one or more non-volatile mass storage devices. In laptop computers, the type of mass storage device generally employed is a storage disc or discs, sometimes referred to as xe2x80x9chard discs.xe2x80x9d Hard discs are provided as part of a Winchester-type disc drive unit having the storage discs supported in a stack on a rotary spindle within a substantially sealed disc drive housing. Winchester-type disc drives are commonly referred to as hard drives, hard disc drives, or simply disc drives. Disc drives are the preferred form of mass storage device in laptop computers as they provide a stable, high capacity, and low cost mechanism for the storage of computer data.
In a typical laptop computer the disc drive is mounted some distance away from the computer motherboard in a disc drive bracket on the inside of the laptop case. While this type of mounting arrangement provides for the stable retention of the disc drive in the laptop case, the process of mounting the disc drive bracket to the case and then mounting the disc drive in the bracket consumes valuable time, and thus costs, in the laptop production process. Additionally, the disc drive bracket consumes valuable space in the laptop case.
Once the disc drive is mounted in the case, the disc drive is generally connected to the motherboard via a ribbon cable. A ribbon cable comprises a flat, flexible cable containing a plurality of electrical wires that are aligned in a row. Attached at each end of the ribbon cable is connector having a plurality of female slots. Soldered to both the motherboard and the disc drive is a male connector having a plurality of pins which are spaced so as to align with the female slots of the ribbon cable connector. The connectors on the ribbon cable are attached to the connectors on the motherboard and disc drive, thereby establishing an electrical connection between disc drive and the motherboard via the ribbon cable.
While the use of ribbon cables and connectors has become commonplace in computers, including laptop computers, there are a number of disadvantages associated with the use of ribbon cables and connectors to connect the disc drive to the motherboard. For example, the capacitance which is inherent in the ribbon cable, the male and female connectors, and the solder used to attach the male connectors to the disc drive and the motherboard causes a decreased electrical efficiency and a lowering of the signal transfer rates between the motherboard and the disc drive. Additionally, the process of soldering the male connectors to the motherboard and disc drive is time intensive and costly. Also, the cost of the cable and the connectors adds to the cost of manufacturing the disc drive. Finally, the cables and connectors consume valuable space within the laptop computer case.
In addition to or in place of disc drives, laptop computers may also use other types of non-volatile mass storage devices, such as electrically erasable programmable read-only memory (EEPROM) or flash memory. EEPROM and flash type memories are silicon, or transistor based solid state devices. Hand held computing devices generally use EEPROM or flash memory type mass storage device. EEPROM and flash type memories may either be built into the laptop or hand held device or, more commonly, plugged into Personal Computer Memory Card International Association (PCMCIA) slots or Peripheral Component Interface (PCI) slots in the laptop or hand held device.
The small size and low power requirements of EEPROM and flash type memories have made them an attractive substitute for disc drives in mobile computing devices. However, recent advances in disc drive technologies, particularly in the area of size reduction and storage bit density, have made disc drives an increasingly attractive alternate to EEPROMs and flash type memories, particularly in hand held computing devices.
The primary advantage of disc drives over EEPROM and flash type memories is that disc drives are volumetrically more efficient. That is, disc drives provide greater data storage densities per device unit volume than do EEPROM or flash type memories. This ratio of device volume to memory capacity is known as the volumetric ratio of the device. For example, at the present time a typical 1.8 inch form factor ATA disc drive has about a 2 to 1 advantage in volumetric ratio to a flash memory device. As the form factor of the disc drive increases, so does the volumetric ration. For instance, at the present time a typical 2.5 inch form factor ATA disc drive has about a 8 to 1 volumetric ratio advantage over a flash memory device.
Additionally, the increase in volumetric ratios for EEPROM, flash type memories, and other silicon based memory devices is governed by Moore""s Law, that is, the capacity or volumetric ratio of the EEPROM or flash type memory device doubles in capacity approximately every eighteen months. In contrast, the doubling of capacity in disc drives has been occurring about every twelve months. If such trends persist, disc drives will continue to widen their advantage in volumetric ratio compared to EEPROM, flash type memories, and other silicon based memory devices.
In addition to their superior volumetric efficiencies, disc drives also surpass flash memory devices in inherent transfer rates. The inherent transfer rate of a device is the rate at which the device transfers information from source to destination, for example, from the disc in the disc drive or the transistors in the flash memory to the output pads or pins of the device. Transfer rate is measured in units of information per unit of time, for example bits per second or characters per second. At present, disc drives have an inherent transfer rate approximately 10 times the inherent transfer rate of EEPROMS or flash type memory devices.
Against this backdrop the present invention has been developed. One aspect of the present invention is to provide an apparatus for electrically connecting a disc drive printed circuit board (disc drive PCB) to a printed circuit board which is external to the disc drive (external PCB), such as a computer motherboard, without the use of electrically inefficient, costly, and space intensive cables which are commonly used to connect disc drive PCBs to external PCBs. Another aspect of the present invention involves an apparatus which eliminates the time intensive and costly step of soldering connectors to the external PCB and/or disc drive PCB. A further aspect of the present invention involves an apparatus which allows a disc drive to be directly mounted to a external PCB, thus eliminating the need for a disc drive mounting bracket, thereby saving valuable space within the computing device and providing a volumetrically efficient alternative to the use of EEPROM and flash type memory devices in mobile computing devices.
In accordance with these and other aspects, an improved connector of the present invention a connector operable for mounting directly on the disc drive PCB. The connector having a plurality of electrically conductive pins, each of the pins operable for simultaneously contacting one of the electrical contact pads on the disc drive PCB and one of the electrical contact pads on the external PCB when the connector is mounted to the disc drive PCB and the disc drive is mounted to the external PCB.
Another aspect of the present invention relates to a method for making a solderless electrical connection between a disc drive PCB and an external PCB. The method involves the steps of providing a connector having at least one electrically conductive pin having a first end and a second end, mechanically biasing the first end of the electrically conductive pin against the PCB electrical connection pad, and mechanically biasing the second end of the electrically conductive pin against the external PCB electrical connection pad, such that a solderless connection is formed between the PCB electrical connection pad and the external PCB electrical, connection pad.
These and various other features as well as advantages which characterize the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings.